Muffler for pneumatic tools

ABSTRACT

The present invention is a muffler for pneumatic tools. The invention includes a hollow nozzle, with the exhaust port being reduced, and some orifices placed at the center thereof. A connector is assembled into the air inlet of the nozzle that allows it to be coupled to a pneumatic tool. A cover is mated externally onto the exhaust port of the nozzle to accommodate an orifice and air vent of the nozzle. Some exhaust holes are provided onto the surface of cover. A noise deadener is installed between the surface of the cover and orifice of nozzle. The air vents are placed at a reduced wall around an orifice of the nozzle, such that some fluid can flow through the unreduced cross-section, thus maintaining proper pressure and reducing the noise level for an improved performance.

CROSS-REFERENCE TO RELATED U.S. APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT

Not applicable.

REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a muffler for pneumatic tools, and more particularly to an innovative muffler which allows air vents to be mounted onto the reducing wall of a nozzle hole thereof.

2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.

The muffler in the present invention is commonly installed at the exhaust port of pneumatic tools (e.g. pneumatic handles and pneumatic grinders, etc) to reduce the exhaust noise and maintain air pressure for improved performance.

The typical structure of muffler 60 is depicted in FIG. 7, wherein the area of air inlet 61 is less than exhaust port 62, and some auxiliary exhaust holes 63 are placed on the wall of muffler 60. However, when such a structure is used in actual applications, the fluid A discharged from the pneumatic tool will flow from the smaller air inlet 61 to a bigger exhaust port 62 via silencing cotton. Therefore, silencing cotton is one of the major factors for speed reduction of the flow field as well as excessive back pressure of the exhaust port of a pneumatic tool. This will impair the pneumatic efficiency (speed) of muffler and performance of the flow field, and also will increase noise in applications.

Thus, to overcome the aforementioned problems of the prior art, it would be an advancement in the art to provide an improved structure that can significantly improve efficacy.

To this end, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products.

BRIEF SUMMARY OF THE INVENTION

The unique muffler of the present invention has some air vents 14 reduced around orifice 13 of nozzle 10, as shown in FIG. 4. Some fluid (W1) is still sprayed from orifice 13. So, the speed of flow field can be maintained due to the reducing nozzle. With configuration of air vents 14, the other fluid (W2) may flow through an unreduced cross-section, enabling the user to properly adjust the pressure and to reduce the blocking and back pressure of the flow field. Meanwhile, fluid W2 flowing through air vent 14 can also be exhausted smoothly due to an accelerating effect generated by fluid W1 flowing through orifice 13, making it possible to reduce noise levels and improve overall performance.

Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows an assembled perspective view of the present invention.

FIG. 2 shows an exploded perspective view of the present invention.

FIG. 3 shows an exploded sectional view of the present invention.

FIG. 4 shows an assembled sectional view of the present invention.

FIG. 5 shows another cross-sectional view of another preferred embodiment of the present invention.

FIG. 6 shows a chart of a test results of the present invention.

FIG. 7 shows a sectional view of typical muffler structure of the prior art.

DETAILED DESCRIPTION OF THE INVENTION

The features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of a preferred embodiment of the present invention with reference to the accompanying drawings.

FIGS. 1, 2, 3, and 4 are preferred embodiments of the muffler of the present invention.

The present invention includes a hollow nozzle 10, with the exhaust port 11 being reduced. Some orifices 13 are placed at the center. The air inlet 12 is placed at the other end of the nozzle, with its cross-section being bigger than the exhaust port 11. Some air vents 14 of a predefined number are placed onto the reduced wall around orifice 13. The flow speed of gas flowing through orifice 13 is faster than that flowing through air vent 14.

A connector 20 is assembled into an air inlet of nozzle 10. The connector 20 has a coupling part 21, a screw in the preferred embodiment, that allows coupling into a preset exhaust position of existing pneumatic tools (e.g. pneumatic handle, pneumatic grinder, etc).

A cover 30 is mated externally onto exhaust port 11 of nozzle 10 to accommodate orifice 13 and air vent 14 of nozzle 10. Exhaust holes 32 of predefined shape and number are provided onto the surface 31 of cover 30.

A noise deadener 40 may be made of silencing cotton. It is installed between the surface 31 of cover 30 and orifice 13 of nozzle 10.

A porous filtering component 50, such as tubular screen, is placed within the connector 20 to achieve a noise deadening and filtering effect.

FIG. 5 depicts another preferred embodiment of muffler of the present invention. The difference is that the connector 20 b is pre-formed into air inlet of nozzle 10.

Based upon above-specified structural design, the muffler of the present invention is operated as follows:

Referring to FIG. 4, when the muffler is operated, fluid W1 flows from the pneumatic tool into connector 20, and then into nozzle 10 through internal filtering component 50. In such a case, some fluid W1 will be guided by the reduced space of exhaust port 11 and sprayed from orifice 13, then exhausted through noise deadener 40 and exhaust hole 32 of cover 30. The other fluid W2 will be sprayed from air vents 14 in an unreduced cross-section, and then exhausted through noise deadener 40 and exhaust hole 32 of cover 30.

The actual test results regarding the muffler of the present invention are contained in a report shown in FIG. 6, wherein the pneumatic tool is a sandpaper grinder. This test is performed using #180 sandpaper. Different pneumatic tool samples with the muffler of the present invention are represented by 1, 2, and 3 at the top of the report, while the listed Dynabrade Spirit 59020 and Air VANTAGE 5 3/16 tools are prior art pneumatic tools of other brands. The test results listed in the report contain power (W), speed (rpm), air consumption (L/s) with load, noise level (dBA) and weight (Kg). It is thus understood that the muffler of the present invention could really reduce noise levels (dBA) of the pneumatic tool, but also maintain the power (W) and free speed, thereby improving operational performance in applications. 

1. A muffler for pneumatic tools, comprising: a hollow nozzle, having a reduced exhaust port, a plurality of orifices placed at center thereof, and an air inlet bigger than said exhaust port; a plurality of air vents of a predefined number being placed onto a reduced wall around an orifice; a connector, being assembled into an air inlet of the nozzle and being able to be coupled into a preset position; a cover, being mated externally onto the exhaust port of said hollow nozzle to accommodate said orifice and an air vent of the nozzle and having a surface with exhaust holes provided thereof; and a noise deadener, being installed between said surface of said cover and said orifice of nozzle.
 2. The muffler defined in claim 1, wherein said connector can be assembled onto the nozzle.
 3. The muffler defined in claim 1, wherein said connector can be pre-formed into the nozzle.
 4. The muffler defined in claim 1, further comprising: a porous filtering component placed within said connector.
 5. A muffler nozzle for pneumatic tools, comprising: a reduced exhaust port; at least one orifice, being placed onto said exhaust port; an air inlet, having a cross-section thereof bigger than said exhaust port; and a plurality of air vents of a predefined number, being placed into a predefined position on a wall between said air inlet and the exhaust port.
 6. The muffler nozzle defined in claim 5, further comprising: a connector being placed at said air inlet of nozzle, and being able to be configured onto a preset position of a pneumatic tool; a cover is placed externally onto the exhaust; and a noise deadener placed between a surface of said cover and said orifice.
 7. The muffler nozzle defined in claim 6, wherein said connector is assembled onto the nozzle.
 8. The muffler nozzle defined in claim 6, wherein said connector is pre-formed into the nozzle.
 9. The muffler nozzle defined in claim 6, further comprising: a porous filtering component placed within said connector. 